1. Field of the Invention
The present invention relates, in general, to Epstein Barr virus induced (EBI) genes. In particular, the present invention relates to DNA segments coding for EBI 1, EBI 2, or EBI 3 polypeptides; EBI 1, EBI 2, or EBI 3 polypeptides; recombinant DNA molecules; cells containing the recombinant DNA molecules; antisense EBI 1, EBI 2, or EBI 3 constructs; antibodies having binding affinity to an EBI 1, EBI 2, or EBI 3 polypeptide; hybridomas containing the antibodies; nucleic acid probes for the detection of the presence of Epstein Barr Virus; a method of detecting Epstein Barr virus in a sample; and kits containing nucleic acid probes or antibodies.
2. Background Information
Epstein-Barr Virus (EBV) is the cause of infectious mononucleosis, a benign proliferation of infected B lymphocytes (Henle, G., et al., Proc. Natl. Acad. Sci. USA 59(1):94-101 (1968)) and can also cause acute and rapidly progressive B lymphoproliferative disease in severely immune compromised patients or in experimental infection of tamarins (Miller, G., Fields Virol., 2nd ed., 1921-58 (1990)). Infection of human B lymphocytes, in vitro, results in expression of six virus encoded nuclear proteins (EBNAs) and two virus encoded membrane proteins (LMPs) (Kieff and Liebowitz, Fields Virol., 2nd ed., 1889-1920 (1990)), and in substantially altered cell growth (Nilsson and Klein, Adv. Cancer Res. 37(319):319-80 (1982)). EBV infected B lymphocytes recapitulate features of antigen stimulation in enlarging, increasing RNA synthesis, expressing activation antigens and adhesion molecules, secreting Ig and proliferating (Boyd, A. W., et al., J. Immunol. 134(3):1516-23 (1985); Gordon, J., et al., Immunology 58(4):591-5 (1986); Guy and Gordon, Intl. J. Cancer 43(4):703-8 (1989); Nilsson and Klein, Adv. Cancer Res. 37(319):319-80 (1982); Thorley-Lawson, D. A., et al., J. Immunol. 134(5):3007-12 (1985)). Unlike antigen stimulated B lymphocytes, EBV infected B lymphocytes continue to proliferate in vitro as immortalized lymphoblastoid cell lines (LCLs) (Nilsson, K., et al., Intl. J. Cancer 8(3):443-50 (1971)).
EBV effects on lymphocytes have been studied by comparing the properties of EBV-negative [EBV(-)] Burkitt lymphoma (BL) cell lines and EBV-positive [EBV(+)] derivatives, infected by EBV, in vitro (Calender, A., et al., Proc. Natl. Acad. Sci. USA 84(22):8060-4 (1987); Ehlin-Henriksson, B., et al., Intl. J. Cancer 39(2):211-8 (1987); Nilsson and Klein, Adv. Cancer Res. 37(319):319-80 (1982); Rowe, M., et al., Intl. J. Cancer 37(3):367-73 (1986)). EBV(-) BL cells resemble proliferating centroblasts of germinal centers, characteristically expressing CD10, CD20, CD77 (BLA), class II antigen, and the carbohydrate recognized by peanut agglutinin (Calender, A., et al., Proc. Natl. Acad. Sci. USA 84(22):8060-4 (1987); Ehlin-Henriksson, B., et al., Intl. J. Cancer 39(2):211-8 (1987); Favrot, M. C., et al., Intl. J. Cancer 38(6):901-6 (1986); Gregory, C. D., et al., Intl. J. Cancer 42(2):213-20 (1988); Gregory, C. D., et al., J. Gen. Virol. 71:1481-1495 (1990); Gregory, C. D., et al., J. Immunol. 139(1):313-8 (1987); Rowe, M., et al., Intl. J. Cancer 37(3):367-73 (1986); Rowe, M., et al., Intl. J. Cancer 35(4):435-41 (1985)). Both EBV(-) BL cells and centroblasts lack surface IgD and antigens associated with early phases of mitogen stimulation in vitro, including CD23, CD39 and CD30. In general, EBV(+) BL cells closely resemble EBV infected primary B lymphocytes in not expressing CD10 or CD77 and in expressing early activation and differentiation markers, vimentin, Bac-1, Bcl-2, surface IgD and CD44 (Calender, A., et al., Proc. Natl. Acad. Sci. USA 84(22):8060-4 (1987); Ehlin-Henriksson, B., et al., Intl. J. Cancer 39(2):211-8 (1987); Favrot, M. C., et al., Intl. J. Cancer 38(6):901-6 (1986); Gregory, C. D., et al., J. Gen. Virol. 71:1481-1495 (1990); Henderson, S., et al., Cell 65(7):1107-15 (1991); Rowe, M., et al., Intl. J. Cancer 37(3):367-73 (1986); Rowe, M., et al., EMBO J. 6(9):2743-51 (1987); Spira, G., et al., J. Immunol. 126(1): 122-6 (1981); Suzuki, T., et al., J. Immunol. 137(4): 1208-13 (1986)). Experiments with single gene transfer into EBV(-) B lymphoma cells, or with specifically mutated EBV recombinants reveal that EBNA 2, LMP 1 and EBNA 3C are essential for lymphocyte growth transformation and alter cellular or viral gene expression. Expression of EBNA 2 alone in EBV(-) BL cell lines results in enhanced transcription of CD23, CD21 (Cordier, M., et al., J. Virol. 64(3):1002-13 (1990); Wang, F., et al., J. Virol. 64(5):2309-18 (1990); Wang, F., et al., Proc. Natl. Acad. Sci. USA 84(10):3452-6 (1987)), and c-fgr (Knutson, J. C., J. Virol. 64(6):2530-6 (1990)). EBNA 2 also transactivates the LMP promoters (Fahraeus, R., et al., Proc. Natl. Acad. Sci. USA 87(19):7390-4 (1990); Wang, F., et al., J. Virol. 64(7):3407-16 (1990)). Analysis of a series of EBNA 2 mutants indicates that the ability of EBNA 2 to transactivate gene expression is tightly linked to its essential role in cell growth transformation (Cohen, J. I., et al., J. Virol. 65(5):2545-54 (1991)). LMP 1 is also critical to EBV's effects on cell growth. LMP 1 transforms immortalized rodent fibroblasts (Baichwal and Sugden, Oncogene 2(5):461-7 (1988); Wang, D., et al., Cell 43:831-40 (1985)) and induces vimentin, Bcl-2 and many of the activation markers and adhesion molecules that EBV induces in BL cells (Birkenbach, M., et al., J. Virol. 63(9):4079-84 (1989); Henderson, S., et al., Cell 65(7):1107-15 (1991); Wang, D., et al., J. Virol. 62(11):4173-84 (1988)). In EBV(-) BL cells, EBNA 3c induces higher level expression of CD21 (Wang, F., et al., J. Virol. 64(5):2309-18 (1990)).
Since altered B lymphocyte gene expression is a central theme in EBV induced changes in B lymphocyte growth, a more complete description of the repertoire of EBV induced genes would be advantageous prior to the investigation of specific genes for their role as mediators of EBV effects on cell growth. Also, because of the similar effects of EBV and antigen, EBV induced genes are likely to include mediators of antigen induced B lymphocyte growth or differentiation. Previously, recognition of such genes has been largely based on increased expression of lymphocyte surface markers (Calender, A., et al., Proc. Natl. Acad. Sci. USA 84(22):8060-4 (1987)), defined by monoclonal antibodies derived against EBV or antigen activated B lymphocytes. Few of these surface markers are likely candidates for important effectors of EBV or antigen induced alterations in lymphocyte growth. The experiments described here use subtractive hybridization to identify cDNA clones of RNAs which are more abundant in an in vitro infected EBV(+) BL cell than in the non-infected EBV(-) control BL cell.